They jumped in and started playing with an AR drone, a hackable quadcopter that you can control with your phone. The AR drone runs Linux on board, has sonar sensors, and two built-in cameras. The only problem with the AR drone is the fact that you only get a short time on each battery. While you could theoretically purchase a whole bank of batteries and cycle through them, it could be difficult to develop and test while constantly swapping batteries. Especially if you add any power-sucking peripherals, like a Dropcam.

Tara and Sean tackled this issue by tethering their AR Drone. By modifying the power connector, they were able to run the AR drone from a PC power supply and 30 feet of 14-gauge speaker wire. They can now indefinitely run the quadcopter while they test things out and play, at least as long as the motors will run. With only one week at the facility, they didn't go beyond mounting the Dropcam and the figuring out the tether, but that isn't too bad!

It seems there is some time before the quadcopter decides it is dead. Can you control the power supply to raise the voltage as a function of the current (and resistence) so that the voltage at the quadcopter is constant (e.g. not at the power supply).

You know how bench supplies always have two positive terminals and two negative terminals, and they're always coupled with big (E on its side shaped) shorting links. Well if you remove the shorts, then, run your two thick wires out to the load and two thin wires back to the sense inputs, the power supply will automatically compensate for the voltage drop in the thicker wires.

We actually discussed having a supply change its voltage to accommodate the large drop depending on the current. While it should work, Tara and Sean had limited time during their hacker-in-residence stay.

Another option would have been to supply a higher than needed voltage and provide on board voltage regulation. This would avoid the 4 wire remote sensing and still enable full votage/current at the copter.

I would say that a week is not enough time to do much and they at least got something accomplished. If I were to revisit that effort I would have suggested building a larger quad-copter with greater lift and larger battery options. The tether is a great starter for debug but not a real long term solution, the full benefits of a copter can only be realized un-tethered.

I would say that a week is not enough time to do much and they at least got something accomplished. If I were to revisit that effort I would have suggested building a larger quad-copter with greater lift and larger battery options. The tether is a great starter for debug but not a real long term solution, the full benefits of a copter can only be realized un-tethered.